Hey there, let's get that square icon showing up properly on your devices! I've run into similar headaches before, so here's a step-by-step breakdown of what to check and fix:

1. Double-Check Your Generated Icons #

First, confirm the icons from the generator are set up correctly:

• Open one of the high-density icons (like mipmap-hdpi/ic_launcher.png) in an image editor. Does the blue square fill the entire canvas? If there's unexpected padding, head back to the generator and adjust these settings:
  • Set foreground.space.pad to 0 to remove extra spacing around the foreground element
  • Ensure crop stays at 0 so the background square isn't clipped
• Verify all density variants (mdpi, hdpi, xhdpi, xxhdpi, xxxhdpi) are generated with their required sizes (e.g., mdpi = 48x48px, xxxhdpi = 192x192px)

2. Fix Android Adaptive Icon Overrides (Android 8.0+) #

Android 8.0+ uses adaptive icons by default, which can force your square icon into system-defined shapes. Here's how to bypass that:

• Navigate to your React Native project's android/app/src/main/res/mipmap-anydpi-v26 folder
• If there's an ic_launcher.xml file here, it’s defining an adaptive icon. Replace its content with a direct reference to your square icon:

  <bitmap xmlns:android="http://schemas.android.com/apk/res/android"
      android:src="@mipmap/ic_launcher"
      android:tileMode="disabled" />
  

• Alternatively, delete this ic_launcher.xml file entirely—this forces the system to use your traditional square mipmap icons instead of adaptive ones

3. Update Android Manifest & Rebuild #

• Open android/app/src/main/AndroidManifest.xml and confirm:
  • The launch activity has android:icon="@mipmap/ic_launcher" set (remove any android:roundIcon attribute if you don't want a rounded variant)
• Clean and rebuild your Android project to apply changes:

  cd android && ./gradlew clean && cd .. && npx react-native run-android
  

• Reset your React Native cache to avoid stale assets:

  npx react-native start --reset-cache
  

4. iOS Quick Check (if applicable) #

If you're seeing issues on iOS too:

• Open your Xcode project and go to Assets.xcassets
• Make sure all square icon slots (App Icon - iOS) are filled with the correct sizes
• Verify Info.plist references the asset catalog correctly (it should point to AppIcon by default)

Quick Troubleshooting Tip #

Test on a physical device instead of an emulator—some emulators apply launcher-specific styling that doesn’t match real-world behavior.

内容的提问来源于stack exchange，提问作者cakePHP